How to make AI disable 2nd hero or 3rd hero?

[Pixyy]

For example, if I want AMAI's NE to use Warden as its first hero, and I also want AI not to use any other heroes because they might slow down the upgrade speed of the Warden. What should I do to make it happen? I checked the AMAIStrategyManager. There are options for the hero's bonus amount in the Strategy file. The document does not state whether this value can be set to a negative number. Can I set a very high value for Warden as the first hero and set a negative value for the 2nd and 3rd heroes?